Bug 756700 - Use the power.screen.timeout pref value as a default for the...

Bug 756700 - Use the power.screen.timeout pref value as a default for the power.screen.timeout setting, patch by an anonymous silicon vendor contributor [r=fabrice]

b2g/chrome/content/shell.js

@@ -624,7 +624,7 @@ SettingsListener.observe('language.current', 'en-US', function(value) {
     power.addWakeLockListener(wakeLockHandler);
   };
 
-  SettingsListener.observe('power.screen.timeout', 30, function(value) {
+  SettingsListener.observe('power.screen.timeout', idleTimeout, function(value) {
     if (!value)
       return;